Electric power steering apparatus serving as vehicle steering apparatus assist drivers in steering by electric motors. More specifically, various types of sensors and others detect the steering states of steering members, for example, and control devices control electric motors based on the results of the detection of the steering states so that steering assist forces are applied to steering mechanisms.
It has been proposed that a control device is arranged between an electric motor and a speed reduction mechanism in an axial direction of the electric motor (see, e.g., Patent Documents 1 to 3).
In the electric power steering apparatus discussed in Patent Document 1, there is provided, between a motor housing in the electric motor and a gear housing in the speed reduction mechanism, a circuit case separate from both the housings, and the circuit case houses the control device.
In the electric power steering apparatus discussed in Patent Document 2, a motor case in the electric motor includes a case on the motor main body side and a case on the substrate side connected to a gear housing, and a controller accommodation chamber is defined between the case on the substrate side and the gear housing.
In the electric power steering apparatus discussed in Patent Document 3, a common case is interposed between a motor housing and a gear housing. A motor chamber is defined between the case and the motor housing, and a controller accommodation chamber is defined between the case and the gear housing.    [Patent Document 1] JP 2002-120739 A    [Patent Document 2] JP 2004-135492 A    [Patent Document 3] JP 2000-190856 A